Rapamycin enhances the anti-tumor activity of cabozantinib in cMet inhibitor-resistant hepatocellular carcinoma / 医学前沿

Cabozantinib, mainly targeting cMet and vascular endothelial growth factor receptor 2, is the second-line treatment for patients with advanced hepatocellular carcinoma (HCC). However, the lower response rate and resistance limit its enduring clinical benefit. In this study, we found that cMet-low HCC cells showed primary resistance to cMet inhibitors, and the combination of cabozantinib and mammalian target of rapamycin (mTOR) inhibitor, rapamycin, exhibited a synergistic inhibitory effect on the in vitro cell proliferation and in vivo tumor growth of these cells. Mechanically, the combination of rapamycin with cabozantinib resulted in the remarkable inhibition of AKT, extracellular signal-regulated protein kinases, mTOR, and common downstream signal molecules of receptor tyrosine kinases; decreased cyclin D1 expression; and induced cell cycle arrest. Meanwhile, rapamycin enhanced the inhibitory effects of cabozantinib on the migration and tubule formation of human umbilical vascular endothelial cells and human growth factor-induced invasion of cMet inhibitor-resistant HCC cells under hypoxia condition. These effects were further validated in xenograft models. In conclusion, our findings uncover a potential combination therapy of cabozantinib and rapamycin to combat cabozantinib-resistant HCC.

Pharmacological Activation of RXR-α Promotes Hematoma Absorption via a PPAR-γ-dependent Pathway After Intracerebral Hemorrhage / 神经科学通报·英文版

Endogenously eliminating the hematoma is a favorable strategy in addressing intracerebral hemorrhage (ICH). This study sought to determine the role of retinoid X receptor-α (RXR-α) in the context of hematoma absorption after ICH. Our results showed that pharmacologically activating RXR-α with bexarotene significantly accelerated hematoma clearance and alleviated neurological dysfunction after ICH. RXR-α was expressed in microglia/macrophages, neurons, and astrocytes. Mechanistically, bexarotene promoted the nuclear translocation of RXR-α and PPAR-γ, as well as reducing neuroinflammation by modulating microglia/macrophage reprograming from the M1 into the M2 phenotype. Furthermore, all the beneficial effects of RXR-α in ICH were reversed by the PPAR-γ inhibitor GW9662. In conclusion, the pharmacological activation of RXR-α confers robust neuroprotection against ICH by accelerating hematoma clearance and repolarizing microglia/macrophages towards the M2 phenotype through PPAR-γ-related mechanisms. Our data support the notion that RXR-α might be a promising therapeutic target for ICH.

The perceptions of medical researchers on qualitative methodologies / Percepción de los investigadores médicos en metodologías cualitativas / Percepção de pesquisadores médicos sobre metodologias qualitativas

We aimed to verify doctor's perception of the qualitative research method, via a qualitative study of interviews with questions on the academic profile of doctors and on the methodology. We interviewed 42 professionals, of which 18 had experience with the qualitative method and 24 with the quantitative method. The results showed that knowledge on the qualitative method was virtually nil among "quantitative researchers", who did not value qualitative research, although some of those realized that it would be important to be more accepting in clinical practice. Others only considered the method as subsidiary to quantitative. The majority considered qualitative methods as lacking academic structure, taking too long to conduct empirical studies, and being difficult to publish. All of them criticized the misuse of the method, and the "quantitatives" pointed out the problem of being unable to reproduce. We concluded that widening the use of the qualitative method by doctors requires investment from the beginning of the academic career and participation in qualitative research projects.

El objetivo es verificar la percepción de médicos sobre el método de investigación cualitativa. Se trata de un estudio cualitativo por medio de entrevistas con preguntas sobre el perfil de los médicos y sobre el método. Entrevistamos a 42 profesionales, 18 con experiencia en el método cualitativo y 24 con el cuantitativo. Los resultados mostraron que el conocimiento sobre lo cualitativo es casi nulo entre los "cuantitativistas", que no valoran la investigación cualitativa, aunque algunos se dan cuenta de que sería importante tener un enfoque más amplio en la práctica clínica. Otros la ven como subsidiaria a lo cuantitativo. Sus dificultades para utilizar ese abordaje son: falta de formación, cantidad de tiempo que exigen y problemas de publicación. Todos han criticado el mal uso del método. Los "cuantitativistas" han destacado como fragilidad, la no reproductibilidad. Llegamos a la conclusión de que para ampliar el uso de los abordajes cualitativos entre los médicos es importante invertir en su formación desde el inicio del curso y la participación en proyectos de investigación cualitativa.

Objetivamos verificar a percepção de médicos sobre o método qualitativo de pesquisa. Estudo qualitativo por meio de entrevistas com questões sobre o perfil acadêmico do médico e perguntas abertas a respeito do método. Entrevistamos 42 profissionais, sendo 18 com experiência no método qualitativo e 24 com o quantitativo. Os resultados evidenciaram que o conhecimento sobre o qualitativo é quase nulo entre os pesquisadores "quantitativistas", os quais não valorizam a pesquisa qualitativa, embora alguns percebam que seria importante ter uma postura mais compreensiva na prática clínica. Outros só a veem como subsidiária ao quantitativo. As principais dificuldades da maioria são: falta de formação, tempo longo despendido nos estudos empíricos e dificuldade de publicação. Todos os entrevistados criticaram o mau uso do método, e os "quantitativistas" ressaltaram, como problema, sua não reprodutibilidade. Concluímos que ampliar o uso do método qualitativo por médicos exige investimento na formação desde o início da graduação e participação em projetos de pesquisa qualitativa.

Angiogenic response of advanced glycation end products (AGEs) involves PPAR

Diabetes is associated with increased formation of advanced glycation end products (AGEs), which have been implicated in micro and macrovascular complications of diabetes. Our earlier reports showed proangiogenic effect of AGE-bovine serum albumin (BSA). In order to understand the mechanism of AGE-mediated angiogenesis, the possibility of involvement of peroxisome prolifeator activated receptor (PPAR) , a ligand activated transcription factor was examined. The angiogenic effect was studied in chick chorio allantoic membrane (CAM) and by analyzing angiogenic markers in human umbilical vein endothelial cells (HUVECs) in culture. The involvement of PPAR was investigated using synthetic PPAR agonist GW 1929 and antagonist GW 9662 and by RT-PCR. In CAM assay, PPAR antagonist GW 9662 reversed the AGE-induced effect on vascularity. In HUVECs in culture, GW 9662 reversed the effect of AGE-BSA and decreased the expression of CD 31, E-Selectin and VEGF. RT-PCR analysis showed that treatment with AGE-BSA caused upregulation of PPAR mRNA levels. The reversal of the effect of AGE on angiogenesis by treatment with PPAR antagonists and up-regulation of PPAR gene in HUVECs treated with AGE-BSA suggested the possible involvement of PPAR -dependent downstream pathway in mediating the angiogenic effect of AGE.

Preventive action of curcumin in experimental acute pancreatitis in mouse.

Background & objectives: Curcuma longa (turmeric) has a long history of use in Ayurvedic medicine as a treatment for inflammatory conditions. The purpose of the present study was to investigate the preventive effects of curcumin against acute pancreatitis (AP) induced by caerulein in mouse and to elucidate possible mechanism of curcumin action. Methods: Curcumin (50 mg/kg/day) was intraperitoneally injected to Kun Ming male mice for 6 days, followed by injection of caerulein to induce AP. GW9662 (0.3 mg/kg), a specific peroxisome proliferator-activated receptor gamma (PPARγ) antagonist, was intravenously injected along with curcumin. Murine macrophage RAW264.7 cells were treated with 100 μmol/l curcumin for 2 h, and then stimulated with 0.1 μ g/ml lipopolysaccharide (LPS). Serum amylase and transaminase levels were measured at 10 h after AP. TNF-α level in mouse serum and cell culture medium were detected by ELISA. Expression of PPARγ and NF-κB were analyzed by RT-PCR and Western blot. Results: Curcumin significantly decreased the pancreas injury and reversed the elevation of serum amylase, ALT and AST activities and TNF-α level in mice with AP. Curcumin treatment inhibited the elevation of NF-κB-p65 in the nucleus of mouse pancreas AP group and RAW264.7 cells, but significantly increased the expression of PPARγ. GW9662 could abolish the effects of curcumin on serum levels of amylase, ALT, AST, TNF-α, and NF-κB level. Interpretation & conclusions: Our results suggest that curcumin could attenuate pancreas tissue and other organ injury by inhibiting the release of inflammatory cytokine TNF-α. These effects may involve upregulation of PPARγ and subsequent downregulation of NF-κB.

Duration and Magnitude of Extracellular Signal-Regulated Protein Kinase Phosphorylation Determine Adipogenesis or Osteogenesis in Human Bone Marrow-Derived Stem Cells

PURPOSE: Imbalances between osteogenic and adipogenic differentiation leads to diseases such as osteoporosis. The aim of our study was to demonstrate the differences in extracellular signal-regulated kinase (ERK) phosphorylation during both adipogenesis and osteogenesis of human bone marrow-derived stem cells (BMSCs). MATERIALS AND METHODS: Using troglitazone, GW9662 and U0126, we investigated their role in hBMSC differentiation to adipogenic and osteogenic fates. RESULTS: ERK1/2 inhibition by U0126 suppressed proliferator-activated receptor (PPAR)gamma expression and lipid accumulation, while it decreased the mRNA expression of adipogenic genes (lipoprotein lipase, PPARgamma, and adipocyte protein) and osteogenic genes (type I collagen and osteopontin). ERK phosphorylation was transient and decreased during adipogenesis, whereas it occurred steadily during osteogenesis. Troglitazone, a PPARgamma agonist, induced adipogenesis by inhibiting ERK phosphorylation even in an osteogenic medium, suggesting that ERK signaling needs to be shut off in order to proceed with adipose cell commitment. Cell proliferation was greatly increased in osteogenesis but was not changed during adipogenesis, indicating that ERK might play different roles in cellular proliferation and differentiation between the two committed cell types. CONCLUSION: The duration and magnitude of ERK activation might be a crucial factor for the balance between adipogenesis and osteogenesis in human bone marrow-derived stem cells.

Duration and Magnitude of Extracellular Signal-Regulated Protein Kinase Phosphorylation Determine Adipogenesis or Osteogenesis in Human Bone Marrow-Derived Stem Cells

PURPOSE: Imbalances between osteogenic and adipogenic differentiation leads to diseases such as osteoporosis. The aim of our study was to demonstrate the differences in extracellular signal-regulated kinase (ERK) phosphorylation during both adipogenesis and osteogenesis of human bone marrow-derived stem cells (BMSCs). MATERIALS AND METHODS: Using troglitazone, GW9662 and U0126, we investigated their role in hBMSC differentiation to adipogenic and osteogenic fates. RESULTS: ERK1/2 inhibition by U0126 suppressed proliferator-activated receptor (PPAR)gamma expression and lipid accumulation, while it decreased the mRNA expression of adipogenic genes (lipoprotein lipase, PPARgamma, and adipocyte protein) and osteogenic genes (type I collagen and osteopontin). ERK phosphorylation was transient and decreased during adipogenesis, whereas it occurred steadily during osteogenesis. Troglitazone, a PPARgamma agonist, induced adipogenesis by inhibiting ERK phosphorylation even in an osteogenic medium, suggesting that ERK signaling needs to be shut off in order to proceed with adipose cell commitment. Cell proliferation was greatly increased in osteogenesis but was not changed during adipogenesis, indicating that ERK might play different roles in cellular proliferation and differentiation between the two committed cell types. CONCLUSION: The duration and magnitude of ERK activation might be a crucial factor for the balance between adipogenesis and osteogenesis in human bone marrow-derived stem cells.

Inhibition of acyl-coenzyme A:cholesterol acyltransferase stimulates cholesterol efflux from macrophages and stimulates farnesoid X receptor in hepatocytes

We investigated the mechanism of spontaneous cholesterol efflux induced by acyl-coenzyme A:cholesterol acyltransferase (ACAT) inhibition, and how an alteration of cholesterol metabolism in macrophages impacts on that in HepG2 cells. Oleic acid anilide (OAA), a known ACAT inhibitor reduced lipid storage substantially by promotion of cholesterol catabolism and repression of cholesteryl ester accumulation without further increase of cytotoxicity in acetylated low-density lipoprotein-loaded THP-1 macrophages. Analysis of expressed mRNA and protein revealed that cholesterol 7alpha-hydroxylase (CYP7A1), oxysterol 7alpha- hydroxylase (CYP7B1), and cholesterol 27-hydroxylase (CYP27) were highly induced by ACAT inhibition. The presence of a functional cytochrome P450 pathway was confirmed by quantification of the biliary cholesterol mass in cell monolayers and extracelluar medium. Notably, massively secreted biliary cholesterol from macrophages suppressed the expression of CYP7 proteins in a farnesoid X receptor (FXR)-dependent manner in HepG2 cells. The findings reported here provide new insight into mechanisms of spontaneous cholesterol efflux, and suggest that ACAT inhibition may stimulate cholesterol-catabolic (cytochrome P450) pathway in lesion-macrophages, in contrast, suppress it in hepatocyte via FXR induced by biliary cholesterol (BC).

Synthesis and reactions of B-ketoanilides for biological evaluation

2-Arylidene cycloalkanones react with acetocetanilide to give the corresponding B-ketoanilides Ia-f which react with hydroxyl-amine and/or hydrazine hydrate in acetic acid to give respectively compounds III and compounds V. Compounds I also react with o-phenylene diamine and/or diethyl malonatethiourea to produce respectively compounds VI and compounds VIII. Chemical screening for the products are mentioned

Spasmolytic activity of two synthetic anilide local anaesthetics.

Two basic anilides EA-7 and EA-8 were investigated for their antispasmodic activity against a variety of spasmogens on different tissues from different species of animals and comparison was made with lignocaine. EA-8 was found to be the most potent in this respect, followed by EA-7 and lignocaine. The antispasmodic potency does not correspond to their local anaesthetic potency. This suggests a direct depressant effect on tissues.